clutch problems

Yup, I too feel your master, or slave, is doing an internal bypass.

The CNC comes in different bores - it should have the size stamped inside on the bottom of the reservoir. Rebuild kits easily found at the vendors.

Larry

It could be one or the other, but....
I would check the O rings on the slave first. It sounds like this could be losing pressure and bypassing there.

O rings are cheap for the slave.

Also, it's not a good thing to sit at a light waiting for the light to turn green with the clutch to the floor.

quote:

Originally posted by Throttle man:
I replaced my clutch master cylinder with the aftermarket pim cnc version, and the long throw slave unit two years ago. I have bleed the system several times. The problem is that the car starts to walk or move after the clutch is pedal is held at a stop light for awhile. At first it doesn't do it at all, but then gets worse. I just rebuilt the transaxle, it shifts fine, and the pedal is pretty firm. I am thinking that the clutch master cylinder is bleeding through, there is no fluid loss. Any ideas?

If the fluid seeps past the slave it will leak on the ground. If the master leaks ..it can be internal, and just seep back into the master.. I agree with Coz.. I usually put my car in netural and let off the clutch...check my rear view...and watch for the cross traffic light to turn yellow., Then put it in first and wait for green before I dump it!

...I would like to make a comment concerning the practice of shifting into neutral at a stop light; some of you will agree and some will not; and that's OK because this BB is open to free expression of thought: Shifting into Neutral may save your 'O' rings/cup in the master and slave cylinders, but it is Dangerous because you are not prepared for an 'Life or Death' Emergency, one can not react, In Time, to get the Transaxle back into gear (any gear). An emergency of say; You look in the rearview mirror and see a driver (perhaps drunk) 'Barreling Down' on You at 90 MPH, collision eminate! There are many other stories of Emergencies that I can tell you. Back many years ago, when I was a 17 year old 'Punk' just learning to drive a clutch and stickshift; I was taught to ALLWAYS keep the trans in gear with the foot on the clutch. Not only can you react as fast as possible, in any situation, but should you be rear-ended; your foot is knocked off of the clutch pedal killing the Engine, and stopping the car from being projected out into the middle of the intersection of a Major Thoroughfare where you are 'T' boned and possibly killed. When at a Light, I have the clutch fully depressed, the master and slave are all new and 'Rock Solid'! If these components can not hold 100% pressure for an indefinite length of time; I don't want them in My Pantera! If You do this practice because your leg gets tired, then start 'lifting weights' with your left leg. That is why I see a lot of Girls, in front of me, fiddling to get into gear long after the light has turned Green. NO I am NOT calling anybody on this Board a girl! I present to you the TRUE Story of the young man and his girlfriend stopped at a Red Light, to their right, speeding down a steep incline comes a Semi Tanker Truck; Out-Of-Control. With barely seconds to react He didn't get the Job done. They were plowed over instantly and killed. One may never see a situation as dramatic as this, But my advice is to allways be Ready; someday you might just be very happy that you were. 'O' Rings be damned! That's just my opinion...

quote:

If these components can not hold 100% pressure for an indefinite length of time; I don't want them in My Pantera

I agree with you Marlin.Sounds like sometning wrong with the slave cylinder then get rid of it or fix it.Cheap advice.

Yes, that true too. You might also want to check the line from the slave running to the master to see if you have any leaking going on along the way under the car or a loose fitting somewhere on the lines where they connect.

I have a steel braided line from the slave that connects to a hard line that runs along the frame to the front end and up to the master. I had the same problem. Replaced the Slave, didn't fix the problem, replaced the master and was still losing some pressure.

I then replaced the the steel braided line and have been fine since.

So that might be an option as well.

[QUOTE]Originally posted by lastpushbutton:
If the fluid seeps past the slave it will leak on the ground.

If the fluid is leaking out the level in the reservoir will fall.

If you have an internal leak in the master cylinder the fluid won't drop.

When it creeps go into neutral, lift your foot off the clutch and then apply again and put in first.
If it takes the same amount of time before it creeps forward again it's a master cylinder leak.

Marlin, You make good points, Notice I said when I put it in nuteral, I check my rear view. I also leave space between me and the car in front of me, while i make mental plans of what i woud IF, then play different senerios out in my head. Can I jump the curb? Can I change lanes. Traffic conditions and local matter too. I live and drive often on single lane roads, in a small town. Would I kick it neteral on a hill? Probobly not. Do I belive that your cluch acuation system be bullit proof... definatly!

There is no fluid loss. I like the idea of replacing the clutch line, is it hard to do? I still think(but guessing) it's the master, I didn't have this problem until I sent the transaxle out for repairs and the car sat for 4 months.

Replace the line from the slave to the hard line first. Most of the vendors have these lines and their not expensive.
It screws off and back on at both points. No big deal.

The hard line which is copper tubing, is a lot more work. It's under the car and runs through the frame along side your cooling tubes in a seperate channel to the front trunk and up to the master. Mine does anyway.

Try the steel braided line first.

My other thought is, these things can be a real pain in the butt to bleed the air out of. It took several attempts and 1/2 a bottle of fluid to finally get all the trapped air out of my system.

quote:

Originally posted by Throttle man:
There is no fluid loss. I like the idea of replacing the clutch line, is it hard to do? I still think(but guessing) it's the master, I didn't have this problem until I sent the transaxle out for repairs and the car sat for 4 months.

If there is no fluid loss there are only 2 possibilities.
The first is the master cylinder, the second would have to be some mechanical problem with the clutch that only occurs when it gets hot - perhaps contamination of the clutch plate.

It was the clutch master cylinder! Thanks for the input.

Did you replace it with another CNC or stock type? And would you know the differences between the two?

I put another cnc one. They have a rebuild kit, but I just bought another. As far as the differences, both the old one & new one say cnc on the side & are made of aluminum.

any cross reference to another part anyone, would like the #'s before i start searching. would like a master to last more than a couple of years!
Thanks Mark